Network comprising search functions that are integrated into communication components

ABSTRACT

The invention relates to a network, in which addresses are assigned to communication components, said addresses allowing the components to communicate with one another. Several communication components comprise integrated search functions for determining the addresses of resources that are installed in other communication components. To determine the addresses, each of said search functions sends a first search notification, as a consequence of which each communication component that has been contacted returns a hit response comprising its address. The search function subsequently sends a second search notification containing information concerning the desired resources to at least one of the communication components that have been determined, whereby a communication component that can provide one of the desired resources replies to the second search notification. The resources comprise communication services that can be used in the network and the reply to the second search notification contains specific information concerning the respective communication service. The communication components that reply to the second search notification also forward said second notification to other communication components.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the US National Stage of International ApplicationNo. PCT/DE2003/001900, filed Jun. 6, 2003 and claims the benefitthereof. The International Application claims the benefits of Germanapplication No. 10230684.2 filed Jul. 8, 2002, both applications areincorporated by reference herein in their entirety.

FIELD OF THE INVENTION

The invention relates to a network comprising search functions that areintegrated into communication components.

SUMMARY OF THE INVENTION

In packet-switching networks (IP networks; IP=Internet Protocol) thecomponents in the network communicate by sending and receiving addresseddata packets. To communicate in the network, each component requires aseparate network address. In addition, communication requires knowledgeof the network address of the communication partner. Only then is directcommunication possible, that is to say without the interposition of afurther entity. The network addresses are either permanently associatedwith each component or else are assigned to the component dynamically,that is to say for a limited time, when the components are turned on.This allocation of the network addresses to the components is usuallydone by a server as the central entity in the network. A server of thistype also provides the components in the network with the networkaddresses of other components for the purpose of interchanging data withthem. Such devices for managing network addresses are frequently alsoused in communication networks which operate on the basis of theInternet protocol. These communication networks are referred to asvoice-over IP (VOIP) networks in the literature.

VoIP networks contain not only the communication components used ascommunication terminals, that is to say telephones, telephony andmultimedia PCs etc., but also communication components which haveresources such as gateways. In this context, gateways are devices whichconnect the packet-switching IP network to a circuit-switching network,for example the ISDN, and thus actually allow communication linksbetween communication components in the VOIP network and those in theISDN. When a communication component in an IP network sets up a link toa telephone in an ISDN network, the communication component in the IPnetwork requires the information about what position in the network hasa suitable gateway available. In this case, the “position” does not ornot just denote a geographical position, but rather primarily denotesthe network address of that component in the network which makes the“gateway” resource available to other network components. In addition,the communication component which wants to set up the communication linkrequires further information about the use of the resource, that is tosay for example details about the possible audio codec, address.formats, network port number, etc.

The addresses of the communication components which can be reached inthe inherent network and the details about the usable resources in thenetwork are either stored in each communication component or can beretrieved in a central server, the “gatekeeper”. In both cases, it isnecessary to administrate these data, that is to say both to input themfor the first time and to perform continual data maintenance in theevent of alterations to the network structure or the communicationcomponents.

The Internet-published specification. “The Gnutella ProtocolSpecification V 0.4” discloses a method which communication componentson the Internet can use to find other communication components in orderto interchange files with them. In this case, the data interchange takesplace not using a central server or gatekeeper but rather in directcommunication between the communication components. Such networks,which, without a superordinate entity, provide direct data interchangebetween communication components, are also. called peer-to-peernetworks, and the communication components, which comprisefunctionalities both from the “clients” and from the “servers” in knownnetworks, are frequently called “servents” in the literature.

In the peer-to-peer network based on the Gnutella specification, eachcommunication component—which are PCs in this case—holds a number offiles ready for interchange with other communication components. Inorder to be able to interchange data, a searching communicationcomponent requires the network address of another communicationcomponent which holds the sought file ready for retrieval. To this end,the searching communication component first of all sends a first searchmessage, the “ping”. The communication components which receive a “ping”search message of this type respond to the searching communicationcomponent with a hit response, the “pong”. This hit response containsthe network address of the responding communication component and alsothe number of files provided by this communication component forinterchange. In the next step, the searching network component sends asecond search message “query” to a limited number of those communicationcomponents which have responded to the “ping” search message with a“pong”. This second search message contains the file name of the filewhich is being sought. If a component receives a second search message“query” and does not itself hold the sought file ready for interchange,this communication component forwards this second search message toother communication components in the network, whose addresses it hasascertained by means of a “ping” method which has already been carriedout in the past, for example. If the communication component is able toprovide the desired file for interchange, however, it responds to thesecond search message “query” with a second hit response “query hit”,which allows the searching communication component to initiate the filetransfer using commands defined in the Internet protocol.

It has been found to be a drawback of the known methods that the use ofresources requires the information about these resources and theiraddresses in the network to be recorded in one or more central computers(servers, gatekeepers).

These data need to be stored when each resource is started andmaintained in the event of changes, which entails a high level of oftenmanual involvement. In the time between the change of addresses andresources and the data maintenance it is additionally not possible touse the affected resource. The same applies when one of the centralcomputers (servers) fails.

It is an object of the invention to reduce the administrationinvolvement in networks.

This object is achieved by the claims.

The object is achieved by virtue of the resources comprisingcommunication services which can be used in the network, with theresponse to the second search message containing respective specificinformation about the communication service, and by virtue of thecommunication components which respond to the second search message alsoforwarding the second search message to other communication components.As a result, the searching communication component is sent the addressesof a plurality or all of the communication components which provide thesought communication service.

The characterizing features of the dependent claims advantageouslyrefine the arrangement further.

The number of search operations is reduced if the communicationcomponents can store the details about the resources of furthercommunication components which (resources) can be used in the network.

If the second search message is used to ascertain the information storedin a communication component about the usable resources of furthercommunication components, with the response to this search messagecomprising the addresses and the use-related details, the network loadproduced by the search operations is reduced.

The access to resources can be controlled by virtue of the communicationcomponents being able to be used to disable or enable access toindividual or all inherent resources by other communication components.

If the communication components can send and/or respond to both firstand second search messages, the resources which can be used in thenetwork can be found particularly quickly.

Sought resources and communication services are also found reliably inwidely branched networks by virtue of the search function of acommunication component sending at least one first search message andcontinuing to send second search messages until a sought resource hasbeen found in the network and the information transmitted in theresponse to one of the second search messages allows the use of theresource.

It is no longer necessary to manage subscriber directories containingthe network addresses of the communication terminals if the addresses ofcommunication components which (addresses) have been obtained from thehit response and from the response to second search messages can be usedto set up communication links.

A plurality of resources found which are of the same type may have therespectively most suitable one selected from them if the responsecomprises the type and number of available services and also the type ofthe inherent network access, including bandwidth and availability, andthe location information.

An exemplary embodiment of an inventive network having search functionsintegrated into communication components is described below withreference to the drawing. In this case, the single figure shows aschematic illustration of a packet-switching communication network whichis connected to a circuit-switching communication network.

BRIEF DESCRIPTION OF THE DRAWING

The sole FIGURE shows a schematic illustration of a packet-switchingcommunication network which is connected to a circuit-switchingcommunication network.

DETAILED DESCRIPTION OF THE INVENTION

Communication components A1-A4, B1-B11 are connected to one another inthe packet-switching communication network VOIP. The packet-switchingnetwork VOIP is meshed in a hybrid form comprising star-like andring-like networking. In principle, any form of meshing is possible, solong as each communication component A1-A4, B1-B11 can interchange datawith any other component A1-A4, B1-B11 directly or indirectly, that isto say with the interposition of other communication components A1-A4,B1-B11.

The circuit-switching network ISDN contains a communication installationS1 and communication terminals C1-C3. It goes without saying that thecircuit-switching network ISDN can also contain a plurality ofcommunication installations with an arbitrary number of communicationterminals.

The communication components A1, A4 arranged in the packet-switchingnetwork VOIP are each equipped with a gateway function as a resource.This gateway function connects the packet-switching network VoIP to thecircuit-switching network ISDN.

The communication component A3 is equipped with a telephony function.This function can be used to set up and use voice links to all voiceterminals B1, B2 arranged in the packet-switching network VOIP and allother communication components A1-A4, B3-B11 equipped with a telephonyfunction. The communication component A3 can also set up and use voicelinks to communication terminals C1-C3 which are arranged in the ISDN.To this end, the communication component A3 first needs to set up aconnection to a gateway provided on the communication component A1 as aresource.

To set up a voice link, starting from the communication component A3 inthe packet-switching network VOIP to the communication component C1arranged in the circuit-switching network ISDN, the telephony functioninstalled on the communication component A3 requires the address of thecommunication component A1 and also the access parameters anduse-related information from the gateway provided on the communicationcomponent A1. Alternatively, the use of the gateway installed on thecommunication component A4 is possible.

The address of a communication component A1-A4, B1-B11 is in this casethe network address (IP address) which is used to address thecommunication component A1-A4, B1-B1 itself. The resources provided on acommunication component A1-A4, B1-B11 are distinguished using IP portnumbers, which means that each resource is unambiguously addressablefrom the combination of the IP address and the IP port number.

To ascertain the address of the communication component A1, thetelephony function of the communication component A3 sends a firstsearch message to a number of further communication components A2, B6.Besides the address of the sending communication component A3, thisfirst search message comprises the information that this communicationcomponent is searching for other communication components A1-A4, B1-B11which support the search method being used for components and resources.Since the two addressed communication components A2, B6 support thesearch method, they each return a hit response containing their ownaddress to the communication component A3. The communication componentA3 then sends a second search message to all communication componentsA2, B6 which have responded to the first search message with a hitresponse. This second search message again comprises the address of thesearching communication component A3, but this time including theinformation about what type of resource is being sought, namely agateway to a circuit-switching network. Since the communicationcomponent A2 does not have a resource of the sought type “gateway”, itforwards the second search message to further, neighboring communicationcomponents A1, B3. The communication component B6 likewise has noresource of the sought type, which means that the communicationcomponent B6 also forwards the second search message to othercommunication components B5, B4 it knows which likewise support thesearch method which is being used.

The communication component A1 has a resource of the sought type“gateway”. It responds to the second search message by sending thesearching communication component A3 a response message which, besidesits own network address, comprises information about the resources itprovides. This information includes details about the IP port number,the number of available channels, the transmission bandwidth of thechannels, the transmission standards which can be used, the location,etc. This information is then used by the communication component A3 toset up a voice link to the communication terminal C1 via the gateway ofthe communication component A1 and the circuit-switching communicationinstallation S1, provided that the use of this resource is enabled inthe communication component A1.

Although the communication component Al has been able to respondpositively to the second search message from the communication componentA3, which was sent to it-by the communication component A2, with thedetails about the gateway installed on it, it nevertheless forwards thesecond search message to communication components A4, B7 which it knowswhich likewise support the search method. The communication component A4also has a gateway to the circuit-switching network ISDN and thereforereturns a data record containing its address and the information aboutthe gateway to the originally searching communication component A3. Thecommunication component A3 thus receives information about the tworesources of the type “gateway” which have been found in thepacket-switching network VOIP.

The information about the resources found in the packet-switchingnetwork VOIP are stored in the communication component A3. If, at alater time, another of the communication components A1-A4, B1-B11requires a gateway to the circuit-switching network ISDN in order to setup a voice link and, in the course of the search method, sends a secondsearch message to the communication component A3, the communicationcomponent A3 responds to the search message using the storedinformation, even though it, itself, does not have a resource of thedesired type, but can nevertheless provide the addresses and theuse-related information about such resources. To this end, thecommunication component A3 can both send and respond to first and secondsearch messages.

Both each searching communication component A1-A4, B1-B11 and the othercommunication components A1-A4, B1-B11 addressed during the search,continue the operation of sending and responding to first and secondsearch messages until at least one resource of the type which is beingsought has been found. In this case, however, limiting the network loadrequires limits to be prescribed which limit both the number ofcommunication components A1-A4, B1-B11 addressed by a first or a secondsearch message and the number of times that a second search messagewhich has not received a positive response is forwarded from onecommunication component A1-A4, B1-B11 to the next.

1-9. (canceled)
 10. A network, comprising: communication componentshaving associated addresses, wherein the communication components areadapted to communicate with one another by using the addresses, whereina first plurality of the communication components has resources, theresources comprising a communication service usable in the network,wherein search functions are integrated in a second plurality of thecommunication components for ascertaining the addresses of suchcommunication components having resources, wherein each search functionis adapted to send a first search message which prompts eachcommunication component reached by the first search message to return ahit response containing its address, wherein each search function isfurther adapted to send at least a second search message comprisinginformation about required resources to at least one of the ascertainedcommunication components, wherein at least one of the ascertainedcommunication components which is able to provide the required resourcesresponds to the second search message, wherein the response to thesecond search message contains information about the communicationservice, and wherein the communication components responding to thesecond search message forward the second search message to othercommunication components.
 11. The network as claimed in claim 10,wherein the communication components are adapted to store details aboutthe resources of the communication components which can be used in thenetwork.
 12. The network as claimed in claim 10, wherein the secondsearch message is designed to ascertain the information stored in acommunication component about the usable resources of the communicationcomponents, wherein the response to this search message comprises theaddresses and use-related details.
 13. The network as claimed in claim11, wherein the second search message is designed to ascertain theinformation stored in a communication component about the usableresources of the communication components, wherein the response to thissearch message comprises the addresses and use-related details.
 14. Thenetwork as claimed in claim 10, wherein the communication components areadapted to disable or enable access to individual or all inherentresources of a communication component.
 15. The network as claimed inclaim 11, wherein the communication components are adapted to disable orenable access to individual or all inherent resources of a communicationcomponent.
 16. The network as claimed in claim 12, wherein thecommunication components are adapted to disable or enable access toindividual or all inherent resources of a communication component. 17.The network as claimed in claim 10, wherein the communication componentsare designed to respond to the first and the second search messages. 18.The network as claimed in claim 11, wherein the communication componentsare designed to respond to the first and the second search messages. 19.The network as claimed in claim 12, wherein the communication componentsare designed to respond to the first and the second search messages. 20.The network as claimed in claim 10, wherein the search function of acommunication component is adapted such that it sends at least one firstsearch message and continues to send second search messages until asought resource has been found in the network and the informationtransmitted in the response to one of the second search messages allowsthe use of the resource.
 21. The network as claimed in claim 11, whereinthe search function of a communication component is adapted such that itsends at least one first search message and continues to send secondsearch messages until a sought resource has been found in the networkand the information transmitted in the response to one of the secondsearch messages allows the use of the resource.
 22. The network asclaimed in claim 12, wherein the search function of a communicationcomponent is adapted such that it sends at least one first searchmessage and continues to send second search messages until a soughtresource has been found in the network and the information transmittedin the response to one of the second search messages allows the use ofthe resource.
 23. The network as claimed in claim 10, wherein theaddresses of communication components which have been obtained from thehit response and from the response to second search messages can be usedto set up communication links.
 24. The network as claimed in claim 11,wherein the addresses of communication components which have beenobtained from the hit response and from the response to second searchmessages can be used to set up communication links.
 25. The network asclaimed in claim 12, wherein the addresses of communication componentswhich have been obtained from the hit response and from the response tosecond search messages can be used to set up communication links. 26.The network as claimed in claim 10, wherein the response comprises atype and a number of available resources and/or available communicationservices and also a type of an inherent network access, includingbandwidth and availability, and a location information.
 27. The networkas claimed in claim 11, wherein the response comprises a type and anumber of available resources and/or available communication servicesand also a type of an inherent network access, including bandwidth andavailability, and a location information.
 28. A method for autonomouslyadministrating a network having communication components which haveassociated addresses and which communicate with one another using theseaddresses, wherein some of the communication components have resources,the resources comprising a communication service which can be used inthe network, the method comprising: determining the addresses ofcommunication components which have resources by using search functionsintegrated in some of the communication components, wherein each of thesearch functions determines the addresses by sending a first searchmessage which prompts each communication component reached by the firstmessage to return a hit response containing its address; sending atleast one second search message comprising information about requiredresources to at least one of the determined communication components bythe search function, wherein at least one of the communicationcomponents which is able to provide the required resources responds tothe second search message, wherein the response to the second searchmessage contains specific information about the communication service;and forwarding the second search message to other communicationcomponents by the communication components which respond to the secondsearch message.